In the past, various different systems have been utilized in various different environments, such as nursing homes for the aged, hospital wards, and institutions for the mentally impaired or the like for instance, in an attempt to control the wandering and/or escape from a confining space in such environments of the patient or residents of such environments.
One of the past security systems shown in U.S. Pat. No. 4,555,696 for utilization in the aforementioned environments employed a mat positioned in a passageway, and a plurality of magnetically operated switches within the mat were electrically interconnected with an alarm. Shoes having a magnetic material inner sole were provided for patients or residents of the aforementioned environments, and magnetic material inner soles effected the magnetic operation of the switches when the patient placed his shoe on the mat. The magnetic operation of the switches energized the alarm to sound a warning to the staff of the attempted egress through the passageway of the patient. At least one of the disadvantages or undesirable features of the above discussed past security systems is believed to be that a bare foot patient could step on the mat without magnetically actuating the switches thereby to egress through the passageway without sounding the alarm.
Another of the past security systems shown in U.S. Pat. No. 3,564,501 discloses a microwatt radio transmitter worn by a user for transmitting radio frequency signals to a receiver associated with circuity for unlocking a door through which the user desires to pass as the user approaches the door. One of the disadvantageous or undesirable features of the above discussed security system is believed to be that the receiver may be actuated by various stray or random radio frequency signals thereby to effect random or unwanted unlocking of the door.
In still another past security system shown in U.S. Pat. No. 4,682,155, a small radio transmitter was worn by a patient in one of the aforementioned environments for transmitting radio frequency signals to a receiver associated with a door, and upon receiving such signals, the receiver energized an alarm at a remote station to alert the staff on duty at such remote station that the patient was attempting to egress through the door. At least one of the disadvantageous or undesirable features of this above discussed past security system is believed that the receiver may be actuated by stray radio frequency signals, as mentioned hereinabove.